Electrophysiological Studies of the Visual System in Mentally Retarded Children Part II: Visual Evoked Potentials

1973 ◽  
Vol 10 (3) ◽  
pp. 223-225
Author(s):  
Y Shapira ◽  
G Szabo ◽  
S Merin ◽  
E Auerbach
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Mentally Retarded ◽  
Electrophysiological Studies ◽  
Mentally Retarded Children ◽  
Visual Evoked

Nonlinear Analysis of Visual Evoked Potentials Elicited by Color Stimulation

1997 ◽  
Vol 36 (04/05) ◽  
pp. 315-318 ◽  
Author(s):  
K. Momose ◽  
K. Komiya ◽  
A. Uchiyama
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Normal Subjects ◽  
Second Order ◽  
First Order ◽  
The Relationship ◽  
Perceived Color ◽  
Second Order Nonlinearity ◽  
Visual Evoked

Abstract:The relationship between chromatically modulated stimuli and visual evoked potentials (VEPs) was considered. VEPs of normal subjects elicited by chromatically modulated stimuli were measured under several color adaptations, and their binary kernels were estimated. Up to the second-order, binary kernels obtained from VEPs were so characteristic that the VEP-chromatic modulation system showed second-order nonlinearity. First-order binary kernels depended on the color of the stimulus and adaptation, whereas second-order kernels showed almost no difference. This result indicates that the waveforms of first-order binary kernels reflect perceived color (hue). This supports the suggestion that kernels of VEPs include color responses, and could be used as a probe with which to examine the color visual system.

The Orientation Anisotropy and Orientation Constancy: A Visual Evoked Potential Study

Perception ◽  
1975 ◽  
Vol 4 (1) ◽  
pp. 51-58 ◽  
Author(s):  
Barrie J Frost ◽  
Jehuda J Kaminer
Keyword(s):  
Visual System ◽  
Evoked Potentials ◽  
Visual Evoked Potentials ◽  
Visual Evoked Potential ◽  
Evoked Potential ◽  
Head Tilt ◽  
Potential Study ◽  
Orientation Anisotropy ◽  
The Subject ◽  
Visual Evoked

Two experiments were conducted on the orientation anisotropy in which averaged visual evoked potentials (VEPs) were recorded from the occipital scalp. The first experiment confirmed the findings of Maffei and Campbell (1970) that obliquely oriented gratings alternated back and forth produced smaller-amplitude VEPs than when the gratings were oriented horizontally or vertically. Since no asymmetry was found in VEPs produced by a Julesz figure presented under identical conditions, it was concluded that direction of displacement could not have been contributing to the effect. In a second experiment head tilt of the subject was manipulated together with grating orientation and the results indicated that the orientation anisotropy is retinally rather than gravitationally referenced. It was concluded that the site of orientation constancy is located either at higher levels of the primary visual system or in the second visual system.

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